Sure, Maura has a cold — maybe even the flu — but she’s going to work anyway. After all, summer is only a few months away, and there’s never enough time to spend at the beach.

And if your sick days are folded into paid time off, like the 34-year-old paralegal’s are, you wouldn’t want to give up any of them either, would you?

Maura, who asked not to use her last name, citing career repercussions, shrugs off possibly infecting her co-workers. “They all have kids — they bring a classroom’s worth of germs into the office,” she says. “They’re like walking petri dishes.”

One might think Maura’s attitude is inconsiderate, but more employees are walking into their workplaces feeling sick rather than staying home until they feel better — even when they know they might be contagious, and even when their employers offer sick days and paid time off.

A study by Staples found that 90 percent of office workers went to work sick in 2012, even though they knew they were ill. And, according to the study, they were only 60 percent as productive as they would have been if they were healthy.

“Everyone has gone to work when they’re ill,” confirms Dr. Steven Lamm, director of the Preston Robert Tisch Center for Men’s Health at NYU Langone Medical Center.

In fact, according to a study conducted earlier this year by NSF International, a global public health and safety organization, 20 percent of Americans never call out sick, no matter how ill they are, and 17 percent stay home only under doctor’s orders.

So why do so many go to their jobs when they should, or could, stay home and take care of themselves? Why do they jeopardize their own well-being and the health of those around them?

Fear of falling behind on their work and missing deadlines is a big reason: The NSF study found that 42 percent of Americans come to work while ill using this rationale.

Lindsey, a former public relations account executive, understands. She trudged into her old job — which offered 10 paid sick days per year — more than once while under the weather because she didn’t want to let her team members down.

“I wasn’t dying,” says the 24-year-old, who declined to give her last name, citing career repercussions. “But I really didn’t feel good.”

She adds that had she been able to access the company’s computer drive from home she definitely would have chosen to work from her apartment.

Lamm says it’s not unusual for sick people like Lindsey to go to work anyway. “It’s called presenteeism,” he says.

Although loss of productivity is an issue for some, it doesn’t always factor into an employee’s decision as to whether they go to work or stay home when ill.

Workplace expert Daryl Pigat, branch manager of Office Team, Robert Half’s Wall Street office, suspects some of the behavior may be a remnant from the recent downturn.

“People want to make sure they’re not forgotten, and they want to show they’re committed to the cause,” he says. “To some, showing up to work every day translates to job security.”

But this isn’t a problem that employers can make rules to fix or spend their way out of, say experts; companies already offer programs to support workers while they are ill — and they’re not being taken advantage of often enough.

“Managers need to lead the change,” says Pigat, meaning that they should stay out of the office themselves when they are ill, to set the right example.

Andrew Royce Bauer, CEO of Royce Leather, a Secaucus, NJ-based leather accessories manufacturer, unintentionally did this last year when he got pneumonia while promoting one of his products. He had no choice but to step back — he was too sick to be effective.

“It was hard,” says Bauer. “It really hurt to do that.”

Dwight Merriman, chairman of Midtown-based software startup MongoDB, says his group of engineers are ultrapassionate about their work. Yet he recently suggested that one of his employees call it a day and go home.

“I didn’t tell him to go,” says Merriman, “but when I asked him how he was doing, and he said he wasn’t feeling well, I suggested it. It seemed to be the logical thing to do.”

And Aron Susman, co-founder of Chelsea-based startup thesquarefoot.com, says showing up to work ill will get you sent home, no questions asked. His team works in extremely tight quarters in an open office plan.

“Asking people to work when they’re sick isn’t moral,” he says. “But neither is coming into the office and infecting everyone else.”